Does Java have a complete enum for HTTP response codes?

Deep dive

Leveraging Apache HttpComponents

Despite the lack of an extensive built-in enum, Apache HttpComponents provides a great alternative. Specifically, the org.apache.http.HttpStatus class houses constants representing all HTTP response codes:

// Using Apache HttpStatus
System.out.println(HttpStatus.SC_NOT_FOUND); // Prints 404: Are we not there yet?
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However, please note that Apache HttpClient's HttpStatus is considered obsolete.

Using Spring for HTTP status codes

Spring Framework offers a detailed enum org.springframework.http.HttpStatus. It's often updated and more exhaustive than standard Java classes:

// Using Spring HttpStatus
HttpStatus status = HttpStatus.valueOf(404);
System.out.println(status.getReasonPhrase()); // Prints "Not Found": Didn't Waldo say something about hiding here?
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Harnessing HttpServletResponse in Servlet API

Working with the servlet environment? The javax.servlet.http.HttpServletResponse interface should be your go-to. It contains all HTTP response codes as int constants and supports conversions:

// Using HttpServletResponse
System.out.println(HttpServletResponse.SC_NOT_FOUND); // Prints 404: feel like we've been here before! 
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Building a custom HttpStatusCode enum

If you're a code wizard, create your own HttpStatusCode enum. Have a getByValue() method to retrieve statuses and override toString() for displaying status code descriptions:

public enum HttpStatusCode {
  OK(200, "OK"),
  NOT_FOUND(404, "Not Found"); // ... add more statuses here

  private final int value;
  private final String reason;

  HttpStatusCode(int value, String reason) {
    this.value = value;
    this.reason = reason;
  }

  public static HttpStatusCode getByValue(int value) {
    // Make magic by finding status with int value
  }

  @Override
  public String toString() {
    return this.value + " " + this.reason; // Abracadabra! It's status time!
  }
}
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This custom enum ensures alignment with the official HTTP status code registry.

Best practices and additional resources

Considering servlet specifics

Given servlets are a staple in web applications, you'll often interact with HttpServletResponse. Armed with most standard web communication statuses, it's a reliable reference point.

Staying updated

The Hypertext Transfer Protocol (HTTP) Status Code Registry is an ideal source for up-to-date HTTP codes.

Utilizing official documentation

The Java EE 7 API documentation for javax.ws.rs.core.Response.Status and the Spring documentation for org.springframework.http.HttpStatus provide valuable insights, including extra context to the enum definitions.